Supermagnonic propagation in two-dimensional antiferromagnets

TL;DR

This paper studies how magnons propagate in 2D antiferromagnets after ultrashort exchange perturbations, revealing anisotropic spreading and speeds exceeding typical magnon velocities due to strong magnon interactions.

Contribution

It introduces a neural quantum state approach to predict magnon dynamics, uncovering unprecedented propagation speeds and anisotropic behavior in 2D antiferromagnets.

Findings

Propagation speed up to 40% higher than magnon velocity

Highly anisotropic magnon spreading observed

Strong magnon-magnon interactions enhance propagation

Abstract

We investigate the propagation of magnons after ultrashort perturbations of the exchange interaction in the prototype two-dimensional Heisenberg antiferromagnet. Using the recently proposed neural quantum states, we predict highly anisotropic spreading in space constrained by the symmetry of the perturbation. Interestingly, the propagation speed at the shortest length and time scale is up to 40% higher than the highest magnon velocity. We argue that the enhancement stems from extraordinary strong magnon-magnon interactions, suggesting new avenues for manipulating information transfer on ultrashort length and time scales.